src/Pure/PIDE/resources.scala

clarified signature;

/*  Title:      Pure/PIDE/resources.scala
    Author:     Makarius

Resources for theories and auxiliary files.
*/

package isabelle


import scala.annotation.tailrec
import scala.util.parsing.input.Reader

import java.io.{File => JFile}


class Resources(
  val session_base: Sessions.Base,
  val log: Logger = No_Logger)
{
  resources =>

  def thy_path(path: Path): Path = path.ext("thy")


  /* file-system operations */

  def append(dir: String, source_path: Path): String =
    (Path.explode(dir) + source_path).expand.implode

  def append(node_name: Document.Node.Name, source_path: Path): String =
    append(node_name.master_dir, source_path)


  /* source files of Isabelle/ML bootstrap */

  def source_file(raw_name: String): Option[String] =
  {
    if (Path.is_wellformed(raw_name)) {
      if (Path.is_valid(raw_name)) {
        def check(p: Path): Option[Path] = if (p.is_file) Some(p) else None

        val path = Path.explode(raw_name)
        val path1 =
          if (path.is_absolute || path.is_current) check(path)
          else {
            check(Path.explode("~~/src/Pure") + path) orElse
              (if (Isabelle_System.getenv("ML_SOURCES") == "") None
               else check(Path.explode("$ML_SOURCES") + path))
          }
        Some(File.platform_path(path1 getOrElse path))
      }
      else None
    }
    else Some(raw_name)
  }


  /* theory files */

  def loaded_files(syntax: Outer_Syntax, name: Document.Node.Name): () => List[Path] =
  {
    val (is_utf8, raw_text) =
      with_thy_reader(name, reader => (Scan.reader_is_utf8(reader), reader.source.toString))
    () => {
      if (syntax.load_commands_in(raw_text)) {
        val text = Symbol.decode(Scan.reader_decode_utf8(is_utf8, raw_text))
        val spans = syntax.parse_spans(text)
        val dir = Path.explode(name.master_dir)
        spans.iterator.map(Command.span_files(syntax, _)._1).flatten.
          map(a => (dir + Path.explode(a)).expand).toList
      }
      else Nil
    }
  }

  def pure_files(syntax: Outer_Syntax, dir: Path): List[Path] =
  {
    val roots =
      for { (name, _) <- Thy_Header.ml_roots }
      yield (dir + Path.explode(name)).expand
    val files =
      for {
        (path, (_, theory)) <- roots zip Thy_Header.ml_roots
        file <- loaded_files(syntax, Document.Node.Name(path.implode, path.dir.implode, theory))()
      } yield file
    roots ::: files
  }

  def theory_name(qualifier: String, theory: String): (Boolean, String) =
    if (session_base.loaded_theory(theory)) (true, theory)
    else {
      val theory1 =
        if (Long_Name.is_qualified(theory) || session_base.global_theories.isDefinedAt(theory))
          theory
        else Long_Name.qualify(qualifier, theory)
      (false, theory1)
    }

  def import_name(qualifier: String, dir: String, s: String): Document.Node.Name =
    theory_name(qualifier, Thy_Header.import_name(s)) match {
      case (true, theory) => Document.Node.Name.loaded_theory(theory)
      case (false, theory) =>
        session_base.known_theory(theory) match {
          case Some(node_name) => node_name
          case None =>
            if (Thy_Header.is_base_name(s) && Long_Name.is_qualified(s))
              Document.Node.Name.loaded_theory(theory)
            else {
              val path = Path.explode(s)
              val node = append(dir, thy_path(path))
              val master_dir = append(dir, path.dir)
              Document.Node.Name(node, master_dir, theory)
            }
        }
    }

  def import_name(name: Document.Node.Name, s: String): Document.Node.Name =
    import_name(session_base.theory_qualifier(name), name.master_dir, s)

  def standard_import(base: Sessions.Base, qualifier: String, dir: String, s: String): String =
  {
    val name = import_name(qualifier, dir, s)
    val s1 =
      if (session_base.loaded_theory(name)) name.theory
      else {
        (try { Some(name.path) } catch { case ERROR(_) => None }) match {
          case None => s
          case Some(path) =>
            session_base.known.get_file(path.file) match {
              case Some(name1) if base.theory_qualifier(name1) != qualifier =>
                name1.theory
              case Some(name1) if Thy_Header.is_base_name(s) =>
                name1.theory_base_name
              case _ => s
            }
        }
      }
    val name2 = import_name(qualifier, dir, s1)
    if (name.node == name2.node) s1 else s
  }

  def with_thy_reader[A](name: Document.Node.Name, f: Reader[Char] => A): A =
  {
    val path = name.path
    if (path.is_file) {
      val reader = Scan.byte_reader(path.file)
      try { f(reader) } finally { reader.close }
    }
    else if (name.node == name.theory)
      error("Cannot load theory " + quote(name.theory))
    else error ("Cannot load theory file " + path)
  }

  def check_thy_reader(node_name: Document.Node.Name, reader: Reader[Char],
    start: Token.Pos = Token.Pos.command, strict: Boolean = true): Document.Node.Header =
  {
    if (node_name.is_theory && reader.source.length > 0) {
      try {
        val header = Thy_Header.read(reader, start, strict)

        val base_name = node_name.theory_base_name
        val (name, pos) = header.name
        if (base_name != name)
          error("Bad theory name " + quote(name) +
            " for file " + thy_path(Path.basic(base_name)) + Position.here(pos) +
            Completion.report_theories(pos, List(base_name)))

        val imports = header.imports.map({ case (s, pos) => (import_name(node_name, s), pos) })
        Document.Node.Header(imports, header.keywords, header.abbrevs)
      }
      catch { case exn: Throwable => Document.Node.bad_header(Exn.message(exn)) }
    }
    else Document.Node.no_header
  }

  def check_thy(name: Document.Node.Name, start: Token.Pos = Token.Pos.command,
      strict: Boolean = true): Document.Node.Header =
    with_thy_reader(name, check_thy_reader(name, _, start, strict))


  /* special header */

  def special_header(name: Document.Node.Name): Option[Document.Node.Header] =
  {
    val imports =
      if (Thy_Header.is_ml_root(name.theory)) List(import_name(name, Thy_Header.ML_BOOTSTRAP))
      else if (Thy_Header.is_bootstrap(name.theory)) List(import_name(name, Thy_Header.PURE))
      else Nil
    if (imports.isEmpty) None
    else Some(Document.Node.Header(imports.map((_, Position.none))))
  }


  /* blobs */

  def undefined_blobs(nodes: Document.Nodes): List[Document.Node.Name] =
    (for {
      (node_name, node) <- nodes.iterator
      if !session_base.loaded_theory(node_name)
      cmd <- node.load_commands.iterator
      name <- cmd.blobs_undefined.iterator
    } yield name).toList


  /* document changes */

  def parse_change(
      reparse_limit: Int,
      previous: Document.Version,
      doc_blobs: Document.Blobs,
      edits: List[Document.Edit_Text]): Session.Change =
    Thy_Syntax.parse_change(resources, reparse_limit, previous, doc_blobs, edits)

  def commit(change: Session.Change) { }


  /* theory and file dependencies */

  object Dependencies
  {
    val empty = new Dependencies(Nil, Set.empty)
  }

  final class Dependencies private(
    rev_entries: List[Document.Node.Entry],
    val seen: Set[Document.Node.Name])
  {
    def :: (entry: Document.Node.Entry): Dependencies =
      new Dependencies(entry :: rev_entries, seen)

    def + (name: Document.Node.Name): Dependencies =
      new Dependencies(rev_entries, seen + name)

    def entries: List[Document.Node.Entry] = rev_entries.reverse
    def names: List[Document.Node.Name] = entries.map(_.name)

    def errors: List[String] = entries.flatMap(_.header.errors)

    lazy val loaded_theories: Graph[String, Outer_Syntax] =
      (session_base.loaded_theories /: entries)({ case (graph, entry) =>
        val name = entry.name.theory
        val imports = entry.header.imports.map(p => p._1.theory)

        val graph1 = (graph /: (name :: imports))(_.default_node(_, Outer_Syntax.empty))
        val graph2 = (graph1 /: imports)(_.add_edge(_, name))

        val syntax0 = if (name == Thy_Header.PURE) List(Thy_Header.bootstrap_syntax) else Nil
        val syntax1 = (name :: graph2.imm_preds(name).toList).map(graph2.get_node(_))
        val syntax = Outer_Syntax.merge(syntax0 ::: syntax1) + entry.header

        graph2.map_node(name, _ => syntax)
      })

    def loaded_files: List[(String, List[Path])] =
    {
      names.map(_.theory) zip
        Par_List.map((e: () => List[Path]) => e(),
          names.map(name => resources.loaded_files(loaded_theories.get_node(name.theory), name)))
    }

    def imported_files: List[Path] =
    {
      val base_theories =
        loaded_theories.all_preds(names.map(_.theory)).
          filter(session_base.loaded_theories.defined(_))

      base_theories.map(theory => session_base.known.theories(theory).path) :::
      base_theories.flatMap(session_base.known.loaded_files(_))
    }

    lazy val overall_syntax: Outer_Syntax =
      Outer_Syntax.merge(loaded_theories.maximals.map(loaded_theories.get_node(_)))

    override def toString: String = entries.toString
  }

  private def show_path(names: List[Document.Node.Name]): String =
    names.map(name => quote(name.theory)).mkString(" via ")

  private def cycle_msg(names: List[Document.Node.Name]): String =
    "Cyclic dependency of " + show_path(names)

  private def required_by(initiators: List[Document.Node.Name]): String =
    if (initiators.isEmpty) ""
    else "\n(required by " + show_path(initiators.reverse) + ")"

  private def require_thy(initiators: List[Document.Node.Name], required: Dependencies,
    thy: (Document.Node.Name, Position.T)): Dependencies =
  {
    val (name, pos) = thy

    def message: String =
      "The error(s) above occurred for theory " + quote(name.theory) +
        required_by(initiators) + Position.here(pos)

    val required1 = required + name
    if (required.seen(name)) required
    else if (session_base.loaded_theory(name)) required1
    else {
      try {
        if (initiators.contains(name)) error(cycle_msg(initiators))
        val header =
          try { check_thy(name, Token.Pos.file(name.node)).cat_errors(message) }
          catch { case ERROR(msg) => cat_error(msg, message) }
        Document.Node.Entry(name, header) ::
          require_thys(name :: initiators, required1, header.imports)
      }
      catch {
        case e: Throwable =>
          Document.Node.Entry(name, Document.Node.bad_header(Exn.message(e))) :: required1
      }
    }
  }

  private def require_thys(initiators: List[Document.Node.Name], required: Dependencies,
      thys: List[(Document.Node.Name, Position.T)]): Dependencies =
    (required /: thys)(require_thy(initiators, _, _))

  def dependencies(thys: List[(Document.Node.Name, Position.T)]): Dependencies =
    require_thys(Nil, Dependencies.empty, thys)
}